Rocker arm



Feb. 28, 1961 R. LATHAM Re. 24,941

ROCKER ARM 3 Sheets-Sheet 1 Original Filed April 14, 1958 Feb. 28, 1961LATHAM Re. 24,941

ROCKER ARM 3 Sheets-Sheet 2 Original Filed April 14, 1958 j! INVENTOR.

ya RAYMOND L. L/7THHM.

aw V da/IA! flTTOF/VEVS.

Feb. 28, 1 961 LATHAM Re. 24,941

ROCKER ARM Original Filed April 14, 1958 3 Sheets-Sheet 5 E INVENTOR. ERA YM 0ND L. LATHAM.

United States Patent ROCKER ARM Raymond L. Latham, Detroit, Mich.,assignor to Chrysler Corporation, Highland Park, Mich., a corporation ofDelaware 25 Claims. (Cl. 123-90) Matter enclosed in heavy bracketsappears in the original patent but forms no part of this reissuespecification; matter printed in italics indicates the additions made byreissue.

This invention relates to improvements in a rocker arm especially of thetype used to operate the gas inlet and exhaust valves of an internalcombustion engine.

Numerous stamped, cast, and forged rocker arms well known to the arthave been employed heretofore with varying degrees of success to operatethe valves of an internal combustion engine. A particular type of rockerarm construction comprises a stamped or forged body having a centralanti-friction bushing adapted to be mounted on a rocker supporting shaftand also having oppositely directed projections, one being engageablewith a push rod for operation thereby, and the other being engageablewith the stem of a valve to operate the latter. In such construction thebushing is pressed into an opening within the body and is lubricated bysuitable means. Although such rocker arms have performed with reasonablesuccess, the costs of prefabricating the central bushing, of assemblingthe same into the body of the rocker arm, and of providing suitablelubricating means for the bushing have raised serious objections to theuse of such rocker arms.

It is accordingly an important object of the present invention toprovide a new and improved simplified unitary sheet metal rocker arm andlubricating means therefor which obviate the necessity of a separatepressed fit bushing and which can be readily fabricated by stamping andpunching operations at a fraction of the cost of conventional rocker armassemblies presently known to the art.

Another object is to provide a rocker arm adapted to be pivotallymounted on a cylindrical rocker supporting shaft, the rocker armcomprising a cylindrical-shaped bottom strap adapted to conform to thecontour of the under side of the shaft and to engage the latter closelyin bearing relationship, the strap terminating upwardly at opposite endsin generally radial or lateral push rod and valve stem engagingprojections having axially spaced vertical sides which are crimped orcoined adjacent their junctures with the strap to provide axially spacedupward cylindrical extensions of the strap closely engageable with theshaft in bearing relation and cooperating with said projections to formpockets for receiving lubricating oil adjacent the sides of the shaft.

Another object is to provide such a structure wherein lubricating oil isfed under pressure to the rocker arm strap via a lubricating ductextending axially within the shaft and opening at a lubricating portwhich extends radially through the shaft to the juxtaposed inner surfaceof the strap.

Another object is to provide such a structure wherein the lubricatingoil flows under pressure circumferentially between the strap and theshaft to the aforesaid pockets and thereafter flows freely axially fromthe rocker arm between the latter and shaft at locations above saidupward extensions of the straps, thereby to assure a con- "ice tinuoussupply of fresh lubricating oil at the bearing surfaces and to flush outproducts of wear and abrasion so as to achieve optimum serviceabilitywith a minimum of structural complexity and expense.

Other objects are to provide a rocker arm structure of the foregoingcharacter wherein the aforesaid push rod engaging projection of therocker arm inclines upwardly from the shaft. The adjacent axially spacedupward extensions of the strap cooperate with the latter projection toprovide an oil-receiving pocket of appreciable size. The latterprojection is provided with a dimple or socket formed in its under sideto receive the rounded upper end of a cam actuated push rod. An oilpassage port extends from the latter pocket to the under side of saidpush rod engaging projection at said socket, whereby lubricating oil issupplied to the latter by the combined actions of gravity flow,capillary action, and mechanical agitation resulting from rapidoscillation of the rocker arm during operation.

Other objects of the invention will appear in the following descriptionand appended claims, reference being had to the accompanying drawingsforming a part of this specification wherein like reference charactersdesignate corresponding parts in the several views.

Figure 1 is a fragmentary transverse vertical sectional view through theengine cylinder of an internal combustion engine, showing a rocker armembodying the present invention.

Figure 2 is an enlarged fragmentary view similar to Figure l, withportions of the rocker arm broken away to show details of construction.

Figure 3 is a side elevational view of the rocker arm removed from theengine.

Figure 4 is an elevational view of the rocker arm of Figure 3, lookinginto the open upper and thereof.

Figure 5 is a sectional view taken in the direction of the arrows alongthe line 5-5 of Figure 3.

Figure 6 is a sectional view taken in the direction of the arrowssubstantially along the line 66 of Figure 3.

Figure 7 is a sectional view taken in the direction of the arrows alongthe line 7-7 of Figure 3.

Figure 8 is a perspective view of the rocker arm as seen from above andone side.

It is to be understood that the invention is not limited in itsapplication to the details of construction and arrangement of partsillustrated in the accompanying drawings, since the invention is capableof other embodiments and of being practiced or carried out in variousways. Also it is to be understood that the phraseology or terminologyemployed herein is for the purpose of description and not of limitation.

Referring to Figure 1, an internal combustion engine is shown comprisingan engine block 10 having a number of cylinders, such as cylinder 11,enclosed by a cylinder head 12 secured to the block 10 by bolts 13. Thehead 12 is provided with suitable gas inlet and exhaust ports for eachcylinder, which ports are closed by stern valves, such as valve 14.Suitably mounted on the head 12 is an oil splash pan 15 containing ahollow rocker supporting shaft 16 extending longitudinally of the head12 and mounted thereon. In accordance with customary practice, a numberof cylinders 11 may be arranged in a row, each being associated with aninlet valve and an exhaust valve, which valves are also arranged in arow or bank for operation by a corresponding plurality of rocker arms 17pivotally mounted on shaft 16.

The several rocker arms 17 are substantially identical, each havingoppositely directed valve engaging and push rod engaging projections 1%and 19 extending generally radially or laterally from shaft 16, Figure2. The under side of extension 18 is rounded adjacent its extremity andoverlies the end of the stem of valve 14 t0 As illustrated in Figure 4,the dimple or socket 20 is offset toward one axial side of thetransverse mid plane of the rocker arm, whereas the extension 18 isbiased slightly to the opposite side of said mid plane. Thus the rockerarm illustrated comprises one of a pair associated with the engine inletand exhaust valves respectively. The other rocker arm of the pair may beformed substantially as shown except that the socket 20 and projection18 will be offset oppositely from the socket and projection shown. Sucha construction renders feasible the use of paired rocker arms of broaderaxial width, and accordingly of broader bearing surface as describedbelow, without altering the customary axial spacing between the exhaustand inlet valves associated with each cylinder.

Each valve 14 is maintained in its upward or port closing position bymeans of coil spring 22 arranged coaxially around the stem of the valveunder compression between an annular seat 23 of the head 12 and anannular upper spring retainer 24. The latter is secured to the upper endof the stem of valve 14 by means of a number of annular grooves 25formed therein into which lit the mating projections 26 of twosemi-annular dogs 27. The outer surfaces of the dogs 27 are conicallyshaped and enlarge upwardly to mate with the upwardly enlarging conicalinner surface of annular retainer 24. By virtue of the foregoingstructure, the spring retainer 24 is readily assembled over the upperend of spring 22 and then forced downwardly below the grooves 25.Thereafter the dogs 27 are assembled in position and the retainer 24 isre leased to return to the position shown in Figure 2 by the action ofspring 22, thereby to hold the dogs 27 positively in position. Thestructure is readily disassembled to enable valve repair or replacement.

Referring in more particularity to Figures 2-8, details of the rockerarm 17 are illustrated. Preferably the arm 17 comprises a unitary dishedsheet metal body susceptible of economical fabrication by stamping andpunching operations. The body is provided with a bottom strap 28 ofcylindrical contour coaxial with shaft 16 and adapted to serve as thebearing surface for the rocker arm at the under side of the shaft 16.The opposite upper ends of the strap 28 merge laterally into the bottomportions of the declining projection 18 and the inclining projection 19respectively. Thus as illustrated in Figure 2, approximately only thelower third of the shaft 16 engages the main portion of the strap 28 inbearing relation.

Extending upwardly from the sides of the projections 18 and 19 are sidewalls 29 which bridge the space above the strap 28 at the centralbroadest portion of the body of the rocker arm 17. From the centralportion of the rocker arm 17, the sides 29 converge toward opposite endsof the projections 18 and 19 and are joined by end walls 30 and 31respectively.

In order to provide for axial passage of the shaft 16, generally coaxialopenings 29a are formed in opposite side walls 29, preferably by lancingoperationsperformed through the open top of the dished rocker arm 17.The openings 29a are somewhat oval in shape and provide a clearance 29bbetween the upper regions of the shaft 16 and juxtaposed portions of theside walls 29. The lower outer edges of the openings 29a are chamferedat 29c, whereas the upper inner edges of the openings 29a are chamferedat 29d.

A significant structure of the present invention illustrated in Figures36 and 8 comprises the portions of the sides 29 adjacent their junctureswith the strap 28 which are coined or creased inwardly at 32 and 33toprovide axially spaced upward extensions 34 and 35 of the cylinj thepush rod engaging projection 19. In

t. 4 v drical strap 28 at opposite sides of the shaft 16. As illustratedin Figure 6, the cylindrical bearing surface of strap 28 which engagesshaft 16 is formed to extend upwardly around the left end of shaft 16 asviewed in Fig. ure 3, substantially to the shading line 36, andthereafter merges with the push rod engaging projection 19. Shading line36 extends substantially horizontally and axially at its mid region,then curves upwardly at its axial opposite ends to form extensions 35.

Similarly, but less pronounced, as illustrated in Figure 5, thecylindrical bearing surface of strap 28 which engages shaft 16 is formedto extend around the right end of shaft 16 as viewed in Figure 3,substantially to the shading line 37 and merges with the valve engagingprojection 18. Shading .line 37 extends substantially horizontally andaxially at its mid region, then curves upwardly at its axially oppositeends to form the extensions 34. By the foregoing structure, the bearingsurface for shaft 16 is increased and in cooperation with the juxtaposedprojections 18 and 19, oil retaining pockets are formed adjacent theshaft 16.

As illustrated in Figures 2 and 3, the coined portions 33 at the axialedges of the cylindrical strap 28 extend upward concentrically with theshaft 16 to the level of a radial line 42a located appreciably above thecentral portion of the bottom strap 28 which merges leftward withconsequence, an oil retaining pocket 38 is formed in the region belowline 42a between shaft 16, the sides and bottom of projection 19, andthe coined projections 33.

Lubricating oil is pumped under pressure into hollow shaft 16 and isdischarged via a radial port 39 to the inner bearing surface of strap 28and thence to pocket 38 by means of an oil groove 40 formed in thecentral portion of strap 28. Above the extensions 35 of the cylindricalbearing surface of strap 28, excess oil will readily flow axiallyoutwardly from the dished rocker arm 17 through clearance 29b, therebyto assure that a continuous flow of fresh cooling lubricant willproperly oil the bearing surfaces between the shaft 16 and strap 28 andwill flush particles of wear therefrom to be trapped by a suitablefilter system. Extending from the region of pocket 38 through the bottomof projection 19 is a lubricating port 41 which supplies oil by leakageto the under side of dimple or socket 20, thence by capillary action tothe upper rounded end of push rod 21.

A pocket structure similar to the pocket 38 at the left of shaft 16 isillustrated in Figures 2 and 5 at the right of shaft 16. In thisinstance, the coined portions 32 at the axial edges of the cylindricalstrap 28 extend upward concentrically with shaft 16 to the level ofradial line 42 located slightly above the central portion of the strap28 which merges to the right with the valve engaging projection 18. Inconsequence, a pocket 43 is formed below the line 42 between the shaft16, sides and bottom of projection 18, and the coined portions 32. It isapparent that the pockets 38 and 43 maintain the level of lubricatingoil above the upper surfaces of the cylindrical strap 28 engaged withshaft 16. Pocket 43 is provided in part to enable a rounded merger ofoptimum radius of curvature between the right end of the central portionof strap 28 and projection 18, thereby to insure increased structuralrigidity for the rocker arm body while at the same time to prevent axialendwise loss of lubricating fluid at regions substantially below theprojection 13. In regard to both extensions 34 and 35, it is to be notedthat the crescent clearance 2% has its smallest dimension adjacent theupper ends of these extensions. Accordingly substantial axial flow oflubricating fluid from the rocker arm 17 does not take place except atlocations somewhat above the lines 42 and 42a. In consequence, the levelof the lubricating fluid readily builds up over the crest of the base ofthe declined projection 18 and end wall 30.

In accordance with the foregoing, a bearing surface of comparativelybroad axial width is achieved with a mum of circumferential extension.The portions of the side walls 29 bridging the openings 29a, incooperation with the end walls 30 and 31, achieve a particularly rigidrocker arm with a minimum of material and weight. The axially spacedcoined portions 32 and 33 at opposite sides of the shaft 16 and closelyconforming to the latter, serve both as additional bearing surfaces andas means to block axial oil flow from the rocker arm 17 until apredetermined desired oil level is obtained.

Summarizing the operation of the structure described, oil is pumpedunder pressure through hollow shaft 16 and thence via port 39 to thebearing surface of strap 28. Circumferentially extending oil passage oroil groove 40 carries oil to the pockets 38 and 43. From pocket 38, theoil flows via port 41 to the underside of socket 20 to lubricate theconnection with push rod 21. From pocket 43, aided by the declination ofprojection 18 and the mechanical agitation of the rapidly oscillatingrocker arm 17 during operation, oil flows over the comparatively shallowend wall 30 and around the under side of projection 18 to lubricate thelatters region of engagement with the stem of valve 14.

I claim:

1. A rocker arm adapted to be pivotally mounted on a cylindricalsupporting shaft, said rocker arm having a cylindrically shaped bottomstrap adapted to conform to the lower portion of the cylindrical contourof said shaft and to engage the same in bearing relation, said strapterminating upwardly at opposite ends in lateral valve stem engaging andpush rod engaging projections respectively, each projection havingaxially spaced sides extending upwardly and joining to bridge the spaceabove said shaft at opposite sides of said strap, said strap at itsaxially opposite sides adjacent its juncture with said push rod engagingprojection having upward extensions conforming closely to the contour ofsaid shaft to restrict the flow of lubricating fluid axially therealongat the regions of said extensions, the latter merging with the axiallyspaced sides respectively of said push rod engaging projection andcooperating therewith to provide a pocket for said fluid.

2. A rocker arm adapted to be pivotally mounted on a cylindricalsupporting shaft, said rocker arm having a cylindrically shaped bottomstrap adapted to conform to the lower portion of the cylindrical contourof said shaft and to engage the same in bearing relation, said strapterminating upwardly at opposite ends in lateral rod en gagingprojections, each projection having axially spaced sides extendingupwardly and joining to bridge the space above said shaft at oppositesides of said strap, said strap at its axially opposite sides adjacentits juncture with one of said projections having upward extensionsconforming closely to the contour of said shaft to restrict the flow oflubricating fluid axially therealong at the regions of said extensions,the latter merging with the axially spaced sides respectively of saidone projection and cooperating therewith to provide a pocket for saidfluid, said one projection being engageable at its under side with a rodand having an orifice extending therethrough from the region of saidpocket to said under side for passage of said fluid.

3. A rocker arm adapted to be pivotally mounted on a cylindricalsupporting shaft, said rocker arm having a cylindrically shaped bottomstrap adapted to conform to the lower portion of the cylindrical contourof said shaft and to engage the same in bearing relation, said strapterminating upwardly at opposite ends in lateral valve stem engaging andpush rod engaging projections respectively, each projection havingaxially spaced sides extending upwardly and joining to bridge the spaceabove said shaft at opposite sides of said strap, said strap at itsaxially opposite sides adjacent its juncture with said push rod engagingprojection having upward extensions conforming closely to the contour ofsaid shaft to restrict the flow of lubricating fluid axially therealongat the regions of said extensions, the latter merging with the axiallyspaced sides respectively of said push rod engaging projection andcooperating therewith to provide a pocket for said fluid, said push rodengaging projection having a dimple in its under side adapted to receivean end of a push rod and also having an orifice extending therethroughfrom the region of said pocket to said under side at said dimple forpassage of said fluid.

4. A rocker arm adapted to be pivotally mounted on a cylindricalsupporting shaft, said rocker arm having a cylindrically shaped bottomstrap adapted to conform to the lower portion of the cylindrical contourof said shaft and to engage the same in bearing relation, said strapterminating upwardly at opposite ends in lateral valve stem engaging andpush rod engaging projections respectively, each projection havingaxially spaced sides extending upwardly and joining to bridge the spaceabove said shaft at opposite sides of said strap, and an oil passagegroove extending circumferentially within the cylindrical surface ofsaid strap to confront said shaft and receive lubricating fluidtherefrom.

5. A rocker arm adapted to be pivotally mounted on a cylindricalsupporting shaft, said rocker arm having a cylindrically shaped bottomstrap adapted to conform to the lower portion of the cylindrical contourof said shaft and to engage the same in bearing relation, said strapterminating upwardly at opposite ends in lateral valve stem engaging andpush rod engaging projections respectively, each projection havingaxially spaced sides extending upwardly and joining to bridge the spaceabove said shaft at opposite sides of said shaft, the region of saidrocker arm at the juncture of said strap with at least one of saidprojections at axially opposite sides of the strap conforming closely tothe cylindrical contour of said shaft to comprise upward extensions ofsaid strap, said upward extensions restricting the flow of lubricatingfluid axially from said rocker arm between the latter and shaft atregions below said upward extensions, and an oil passage grooveextending circumferentially within the cylindrical surface of said strapto confront said shaft and receive lubricating fluid therefrom.

6. A rocker arm adapted to be pivotally mounted on a cylindricalsupporting shaft, said rocker arm having a cylindrically shaped bottomstrap adapted to conform to the lower portion of the cylindrical contourof said shaft and to engage the same in bearing relation, said strapterminating upwardly at opposite ends in lateral valve stem engaging andpush rod engaging projections respectively, each projection havingaxially spaced sides extending upwardly and joining to bridge the spaceabove said. shaft at opposite sides of said shaft, said strap at itsaxially opposite sides adjacent its [junction] juncture with said pushrod engaging projection having upward extensions conforming closely tothe contour of said shaft to restrict the flow of lubricating fluidaxially therealong at the regions of said extensions, the latter mergingwith the axial-1y spaced sides respectively of said push rod engagingprojection and cooperating therewith to provide a pocket for said fluid,said push rod engaging projection having a dimple in its under sideadapted to receive an end of a push rod and also having an orificeextending therethrough from the region of said pocket to said under sideat said dimple for passage of said fluid, and an oil passage grooveextending circumferentially within the cylindrical surface of said strapto confront said shaft and receive lubricating fluid therefrom.

7. A rocker arm adapted to be pivotally mounted on a cylindricalsupporting shaft, said rocker arm having a cylindrically shaped bottomstrap adapted to conform to the lower portion of the cylindrical contourof said shaft and to engage the same in bearing relation, said strapterminating upwardly at opposite ends in lateral valve stem engaging andpush rod engaging projections respectively, each projection havingaxially spaced sides extending upwardly and joining to bridge the spaceabove said shaft at opposite sides of said shaft, said push rod- 7engaging projection inclining from-saidstrap, said valve engagingprojection declining from said strap, and the axial spacing between thesides of at least one of said.

projections adjacent the latters juncture with said strap beingrestricted to provide upward [upwardly] exten sions of said strapconforming closely to the cylindrical contour of said shaft andrestricting the flow of lubricating fluid axially from said rocker armbetween the latter and shaft.

8. A rocker arm adapted to be pivotally mounted on a cylindricalsupporting shaft, said rocker arm having a cylindrically shaped bottomstrap adapted to conform to the lower portion of the cylindrical contourof said shaft and to engage the same in bearing relation, said strapterminating upwardly at opposite ends in lateral valve stem engaging andpush rod engaging projections respectively, each projection havingupwardly extending end walls and side walls, said side walls merging atopposite sides of said strap and bridging the space above said shaft atsaid opposite sides, said push rod engaging projection inclining fromsaid strap, said valve engaging projection declining from said strap,and the axial spacing between the sides of at least one of saidprojections adjacent the latters juncture with said strap beingrestricted to provide upward extensions of said strap conforming closelyto the cylindrical contour of said shaft and restricting the flow oflubricating fluid axially from said rocker arm between the latter andshaft.

9. A rocker arm adapted to be pivotally mounted on a cylindricalsupporting shaft, said rocker arm having a cylindrically shaped bottomstrap adapted to conform to the lower portion of the cylindrical contourof said shaft and to engage the same in bearing relation, said strapterminating upwardly at opposite ends in lateral valve stem engaging andpush rod engaging projections respectively, each projection havingupwardly extending end walls and side walls, said side Walls merging atopposite sides of said strap and bridging the space above said shaft atsaid opposite sides, one of said projections inclining from said strapand the other projection declining from said strap, the axial spacingbetween the sides of said one projection adjacent the latters juncturewith said strap being restricted to provide upward extensions of saidstrap conforming closely to the cylindrical contour of said shaft andrestricting the flow of lubricating fluid axially from said rocker armbetween the latter and shaft and thereby cooperating with said oneprojection to provide a pocket adjacent said shaft for said fluid, saidone projection having a dimple in its under side adapted to receive theend of a shaft and also having an orifice extending therethrough fromthe region of said pocket to said under side at said dimple for passageof said'fluid.

10. A rocker arm adapted to be pivotally mounted on a cylindricalsupporting shaft, said rocker arm having a cylindrically shaped bottomstrap adapted toconform to the lower portion of the cylindrical contourof said shaft and to engage the same in bearing relation, said strapterminating upwardly at opposite ends in lateral valve stem engaging andpush rod engaging projections respectively, each projection havingupwardly extending end walls and side walls, said side walls merging atopposite sides of said strap and bridging the space above said shaft atsaid opposite sides, one of said projections inclining from said strapand the other projection declining from said strap, the axial spacingbetween the sides of said one projection adjacent the latters juncturewith said strap being restricted to provide upward extensions of saidstrap conforming closely to the cylindrical contour of said shaft andrestricting the flow of lubricating fluid axially from said rocker armbetween the latter and shaft and thereby cooperating with said oneprojection to provide a pocket adjacent said shaft for said fluid, saidone projection having a dimple in its under side adapted to receive theend of a shaft and also having an orifice extending therethrough fromthe region of said pocket to,

said under side at said dimple for passage of said fluid,"

11. A rocker arm adapted to be pivotally mounted on.

a cylindrical supporting shaft, said rocker arm having a cylindricallyshaped bottom strap adapted to conform to the lower portion of thecylindrical contour of said shaft and to engage the same in bearingrelation, said strap terminating upwardly at opposite ends in lateralvalve. stem engaging and push rod engaging projections respectively,each projection having upwardly extending end walls and side walls, saidside walls merging at opposite sides of said strap and bridging thespace above said shaft at said opposite sides, one of said projectionsinclining from said strap, the axial spacing between the sides of saidone projection adjacent the latters juncture with said strap beingrestricted to provide upward extensions of said strap conforming closelyto the cylindrical contour of said shaft and restricting the flow oflubricating fluid axially from said rocker arm between the latter andshaft and thereby cooperating with said one projection to provide apocket adjacent said shaft for said fluid, said one projection having adimple in its under side adapted to receive the end of a shaft and alsohaving an orifice extending therethrough from the region of said pocketto said under side at said dimple for passage of said fluid.

12. A rocker arm adapted to be pivotally mounted on a cylindricalsupporting shaft, said rocker arm having a cylindrically shaped bottomstrap adapted to conform to the lower portion of the cylindrical contourof said shaft and to engage the same in bearing relation, said straphaving an upper end terminating in a lateral rod engaging projectionhaving axially spaced sides extending upwardly, said strap at itsaxially opposite sides adjacent its juncture with said rod engagingprojection having upward extensions conforming closely to the contour ofsaid shaft to restrict the flow of lubricating fluid axially therealongat the regions of said extensions, the latter merging with the axiallyspaced sides respectively of said rod engaging projection andcooperating therewith to provide a pocket for said fluid.

13. A rocker arm adapted to be pivotally mounted on a cylindricalsupporting shaft, said rocker arm having a cylindrically shaped bottomstrap adapted to conform to the lower portion of the cylindrical contourof said shaft and to engage the same in bearing relation, said strapterminating upwardly at opposite ends in lateral projections,eachprojection having upwardly extending side walls merging at oppositesides of said strap and bridging the space above said shaft at saidopposite sides,

1 said strap at its axially opposite sides adjacent its juncture withsaid projections having upward extensions [extension] conforming closelyto the contour of said shaft to restrict the flow of lubricating fluidaxially therealong at the regions of said extensions, the latter mergingwith the axially spaced sides respectively [respectievly] of saidprojections and cooperating therewith to provide a pocket for saidfluid.

14. A rocker arm adapted to be pivotally mounted on a cylindricalsupporting shaft, said rocker arm having a cylindrically shaped bottomstrap adapted to conform to the lower portion of the cylindrical contourof said shaft and to engage the same in bearing relation, said straphaving an upper end terminating in a lateral rod engaging projectionhaving axially spaced sides extending upwardly and bridging the spaceabove said shaft at the opregions of said extensions, the latter mergingwith the axially spaced sides respectively of said rod engagingprojection and cooperating therewith to provide a pocket for said fluid.

15. A rocker arm for operating a valve for an internal combustion engineor the like comprising a unitary metal arm formed of a single sheet ofmetal shaped for rigidity in a rocking plane of operation, means at oneend of the arm for operatively connecting to a reciprocable push rodwhereby the arm is pivotally rocked about a pivotal point intermediatethe ends, means at the other end of the arm for operatively engaging avalve stem whereby the reciprocating movement of the push rod may betranslated to a poppet valve, and-bearing means formed integral withsaid single sheet and located at said pivotal point along the arm formounting the arm on an arm supporting shaft which extends transverselyof the arm and transversely of said rocking plane of motion, saidbearing means located coaxial with said pivotal point.

16. A rocker arm for operating a valve for an internal combustion engineor tlte like comprising a unitary metal arm formed of a single sheet ofmetal shaped for rigidity in a rocking plane of operation, means formedfrom said metal sheet at one end of the arm for operatively connectingto a reciprocable push rod whereby the arm is pivotally rocked about apivotal point intermediate the ends, means formed from said metal sheetat the other end. of the arm for operatively engaging a valve stemwhereby the reciprocating movement of the push rod may be translated toa poppet valve, and cylindrical shaped bearing means formed from saidsingle sheet from which the arm is formed located at said pivotal pointfor pivotally attaching said arm to a pivotal support on an enginepermitting pivotal movement in said rocking plane of operation.

17. A rocker arm for operating a valve for an internal combustion engineor the like comprising a unitary metal arm formed of a single sheet ofmetal shaped for rigidity in a rocking plane of operation having abearing formed intermediate the ends and having a wall projectingupright from the arm, means defining a substantially circular opening insaid wall at a location intermediate the ends of the arm and in axialalignment for assembly by sliding over an arm supporting shaft wherebythe rocker arm will be held against displacement about an axisperpendicular t the arm and will be supported on the shaft for pivotalrocking movement, means at one end of the arm for operatively connectingto a reciprocable push rod whereby the arm is pivotally rocked about apivotal point intermediate the ends, and means at the other end of thearm for operatively engaging a valve stem whereby the reciprocatingmovement of the push rod may be translated to a poppet valve.

18. A rocker arm for operating a valve for an internal combustion engineor the like comprising a shaped elongated rocker arm formedsubstantially in its entirety of pressed metal plate, means at one endof the arm for operatively receiving a reciprocable push rod to rock thearm in a substantially vertical plane when used in an upright position,means at the other end of the arm for operatively receiving the stem ofa poppet valve to be operated by the arm with pivotal movement wherebythe reciprocating movement of the push rod is translated to the valve,and a metal plate section of substantially uniform thickness formed fromsaid sheet at the center of the rocker arm shaped with a hollow opencylindrical bearing face with its axis laterally of the rocker arm andfacing upwardly to fit against the cylindrical lower surface of a shaftfor pivotally supporting the rocker arm.

19. A rocker arm for operating a valve for an internal combustion engineor the like comprising a shaped elongated rocker arm formedsubstantially in its entirety of pressed metal plate, means at one endof the arm for operatively receiving a reciprocable push rod to rock thearm in a substantially vertical plane when used in an upright position,means at the other end of the arm for operatively receiving the stem ofa poppet valve to be operated by the arm with pivotal movement wherebythe reciprocating movement of the push rod is translated to the valve,and a metal plate section of substantially uniform thickness at thecenter of the rocker arm shaped with a hollow open cylindrical bearingface with its axis laterally of the rocker arm and facing upwardly tofit against the cylindrical lower surface of a shaft for pivotallysupporting the rocker arm and having portions at the sides of saidbearing face turned upwardly to form side walls for strengthening thearm and having axial openings through each of the side walls larger thanthe supporting shaft to be slid over the shaft in assembly guiding therocker arm in its place on the shaft to prevent displacement of saidbearing face.

20. In a valve in head engine, a valve operating assentbly having anupwardly extending reciprocable push rod, a poppet valve with anoperating stem having an upwardly exposed end, a laterally extendingsupport shaft located between the push rod and poppet valve, a shapedpressed metal rocker arm formed of a single unitary sheet of metal andextending between said push rod and valve stem and pivotally carried onthe support shaft, means at one end of the arm for operatively receivingthe reciprocable push rod to rock the arm in a substantially verticalplane when used in an upright position, means at the other end of thearm for operatively receiving the stem of the poppet valve to beoperated by the arm with pivotal movement whereby the reciprocatingmovement of the push rod is translated to the valve, and an upwardlyfacing cylindrical bearing face intermediate of the ends of the rocketarm pressed into the upper surface of the sheet of metal and carryingthe rocker arm on the lower surface of the support shaft.

21. In a valve in head engine, a valve operating assembly having anupwardly extending reciprocable push rod, a poppet valve with anoperating stem having an upwardly exposed end, a laterally extendingsupport shaft located between the push rod and poppet valve, a shapedpressed metal rocker arm formed of a single unitary sheet of metal andextending between said push rod and valve stem and pivotally carried onthe support shaft, means at one end of the arm for operatively receivingthe reciprocablc push rod to rock the arm in a substantially verticalplane when used in an upright position, means at the other end of thearm for operatively receiving the stem of the poppet valve to beoperated by the arm with pivotal movement whereby the reciprocatingmovement of the push rod is translated to the valve, an upwardly facingcylindrical bearing face intermediate of the ends of the rocker armpressed into the upper surface of the sheet of metal and carrying therocker arm on the lower surface of the support shaft, and meansreinforcing said bearing face to prevent deformation thereof andstrengthen said rocker arm.

22. In a valve in head engine, a valve operating assembly having anupwardly extending reciprocable push rod, a poppet valve with anoperating stem having an upwardly exposed end, a laterally extendingsupport shaft located between the push rod and poppet valve, a shapedpressed metal rocker arm formed of a single unitary sheet of metal andextending between said push rod and valve stem and pivotally carried onthe support shaft, means at one end of the arm for operatively receivingthe reciprocable push rod to rock the arm in a substantially verticalplane when used in an upright position, means at the other end of thearm for operatively receiving the stem of the poppet valve to beoperated by the arm with pivotal movement whereby the reciprocatingmovement of the push rod is translated to the valve, an upwardly facingcylindrical bearing face intermediate of the ends of the rocker armpressed into the upper surface of the sheet of metal and carrying therocker arm on the lower surface of the'supp'o'rt shaft, and side wallsformed of said sheet of metal integral with said rocker arm and turnedupwardly at the sides of the rocker arm to strengthen the bearing faceand rocker arm.

23. A rocker arm for an engine having a push rod and a poppet valvecomprising a unitary rocker arm formed of a single flat plate ofmaterial of substantially uniform thickness, first means formed in thearm at one end for operably receiving a push rod of an engine, secondmeans formed in the arm at the other end of the rocker arm for operablyreceiving the stem of a valve to be operated by reciprocation of thepush rod, said first and second means displaced laterally on oppositesides of an axis of the rocker arm centrally located and extendingparallel to the arm and between its ends, and means formed in the armintermediate the ends and integral with the plate of material forpivotally supporting the arm on a supporting shaft on the engine. h

24. A rocker arm for an engine having a push rod and a poppet valvecomprising a unitary rocker arm formed of a single flat plate ofmaterial of substantially uniform thickness, first means formed in thearm at one end for operably receiving a push rod of an engine, secondmeans formed in the arm at the other end of the rocker arm for operablyreceiving the stem of a valve to be operated by reciprocation of thepush rod, said first and second means displaced laterally with respectto the longitudinal axis of the arm, and an open cylindrical shaped bearing face formed in the arm integral with the plate of materialintermediate the ends and extending laterally with its axissubstantially normal to the axis of the rocker arm and facing upwardlyfor pivotally bearing on a'supportingshaft on the engine.

25. A rocker arm for an engine having a push rod 7 and a poppet valvecomprising a unitary rocker arm formed of a single flat plate ofmaterial of substantially uniform thickness, first means formed in thearm at one end for operably receiving a push rod of an engine,

second means formed in the arm at the other end'of the rocker arm foroperably receiving the stem of a valve to be operated by reciprocationof the push rod, said first and second means displaced laterally onopposite sides of the axis of the rocker arm extending parallel to thearm and between its ends, an open cylindrical shaped bearing face formedin the arm intermediate the ends and extending laterally with its axissubstantially normal to the axis of the rocker arm and facing upwardlyfor pivotally bearing on a supporting shaft on an engine,

a vertical wall formed of said plate material and project-' ing upwardlyto reinforce said arm, and a lateral opening through said vertical wallabove said bearing face where-' Sampietro Feb. 25, 1958

